This one has been failing for quite a while, and I found http://flibs.sourceforge.net/chksys.html as a potential replacement link.
Thoughts? Gerald Index: readings.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/readings.html,v retrieving revision 1.276 diff -u -r1.276 readings.html --- readings.html 11 Apr 2017 22:30:59 -0000 1.276 +++ readings.html 11 Apr 2017 22:39:10 -0000 @@ -436,7 +436,7 @@ possible to stress the compiler error handling. </li> <li> - <a href="http://ftp.cac.psu.edu/pub/ger/fortran/chksys.htm"><cite>Checking + <a href="http://flibs.sourceforge.net/chksys.html"><cite>Checking properties of the compiler and the run-time environment</cite></a> by Arjen Markus (source provided). </li>